Database Reference
In-Depth Information
α (
Definition 50
Given a view V
=
q B ( x )
B of a database B
=
B
) , a model of
the schema
B
, and an insertion request
+
t , we say that database insertion
B is a
translation for
B causes the insertion of t into V when applied to B .More
formally, let V = q B ( x ) B be the new view, obtained from the minimally updated
database B =
+
t if
α 1 (
) , where α 1
B
B
=
B
is the new updated model of
B
, and let
V \
V
=
V be the actual inserted view tuples (the view insertions induced by
B ).
We say that
V .
We denote the update of a model of
B is a VIT for
+
t if t
B
induced by VIT for
+
t over a sin-
M Pn
gle view V by a transition α ====
α 1 , where P n is a sequential composi-
tion of RA arrows in the Application Plan considered as a program of categorial
machine M RC which executes the inserting of tuples in
.
From Proposition 30 in Sect. 6.2.2 , this transition corresponds to the natural trans-
formation η P n :
B of the schema
B
α 1
DB Sch (G( B )) ) such that
α
(an arrow in Int(G(
B
))
α (
α 1 (
f I =
) , defined by Corollary 17 and specified in Exam-
ple 34 as an arrow in DB , is obtained from 'INSERT...' SQL statements used to
insert the tuples in
η P n (
B
)
:
B
)
B
B .
If
V
=
t then
B is an exact translation (i.e., side-effect free) for
+
t . Other-
wise
t .
The algorithms for translating view insertions can be, for example, used from
operations defined in [ 14 ].
B is inexact, that is, with side-effects (or extra insertions) E
=
V
\
Proposition 32 Let us consider a database mapping system ( graph ) G = (V G ,E G )
with a current mapping-interpretation α :
Sch (B)
DB ( i . e ., from Definition 11
and Proposition 16 , α
DB Sch (G) ) which is a model of each database
schema in V G ( but not necessarily satisfies all inter-schema mappings in G ) with
A
Int(G)
α (
=
A
) obtained by inserting some tuples in
A
and there exists
M AB ={
Φ
}∈
E G , where Φ is a normalized SOtgd formula
f
x 1 q A 1 ( x 1 )
r B, 1 ( t 1 ) ∧···∧∀
x m q A m ( x m )
r B,m ( t m )
with M AB =
MakeOperads(
M AB )
={
v 1 ·
q A, 1 ,...,v m ·
q A,m , 1 r }: A B
. Let
S B = (V i ,t i )
α 1 (v i ) ,t i = b
α (
|
V i =
|
d m
α(r i m )
A
),m
=
1 ,...,k,
= =∅
b
=
α(q A,i )( d 1 ,..., d k )
=
,α(v i )( b )
,
for v i ·
q A,i
MakeOperads(
M AB ),
O(r q ,r i )
q A,i
O(r i 1 ,...,r i k ,r q ),v i
, t i
be a nonempty set where for each element (V i ,t i )
t i is
a subset of tuples accepted to be consecutively inserted into the view V i ( here just
a relation α(r i ) of a database
∈S B
, 1
i
n
=|S B |
and hence if t i =
t i then all transitions are exact ,
i . e ., side-effect free ), then the concatenation of update transitions ( in Definition 50 )
B
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